Transfer hood



July 30, 1968 AR. GLASGOW, JR 3,394,464

TRANSFER Boob Filed Aug. 21. 1967 INVENTOk Augustus R. Glasgow FIGJ.

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United States Patent 3,394,464 TRANSFER HOOD Augustus R. Glasgow, Jr., Hyattsville, Md., assignor to the United States of America as represented by the Secretary of the Department of Health, Education and Welfare Filed Aug. 21, 1967, Ser. No. 661,992 6 Claims. (Cl. 3436) ABSTRACT on THE DISCLOSURE The present disclosure relates to a transfer hood that fits over a sample vial so that degradable chemicals may be withdrawn from the vial without subjecting the remaining contents of the vial to the ambient atmosphere containing oxygen and water vapor, which tend to degrade the chemicals. The transfer hood tightly fits over the neck of the vial. During use an inert gas is passed into the transfer hood to flush out the ambient atmosphere and while the inert gas continues to flow, the vial may be opened and the chemicals removed and the vial reclosed without being contaminated with ambient atmosphere.

SPECIFICATION The present invention relates to a transfer hood, and, more particularly, to a device for protecting the degradable contents of a vial while portions of the contents are being transferred therefrom.

Many chemicals are relatively unstable toward oxygen and traces of moisture and must be protected to prevent degradation thereof during sampling and storage. This problem has been recognized and certain complex and expensive devices have been designed to permit the transfer of such sensitive chemicals while affording protection against the ambient atmosphere. An example of such a complex device is shown in the Bloomer et al. Patent No. 2,862,307; this patent shows a processing chamber sealed to the atmosphere and including inwardly extending rubher arm and glove members which are adapted to receive the arms and hands of the operator who may manipulate the materials within the sealed chamber. Devices such as this are, however, very expensive and unduly large and are, accordingly, undesirable.

It is, therefore, an object of the present invention to overcome the deficiencies of the prior art, such as indicated above.

It is another object of the present invention to provide for the transfer of sensitive chemicals while affording protection against contamination and decomposition from the ambient atmosphere.

It is another object of the present invention to provide a system utilizing a simplified and inexpensive device while carrying out a procedure to accomplish transfer of sensitive chemicals while affording protection of the container against contamination from the ambient atmosphere.

It is another object of the present invention to provide a novel device which is small and inexpensive, which device facilitates the transfer of mate-rials while protecting same against contamination from the surrounding atmoshere. p It is another object of the present invention to provide a method of transferring a sensitive material from one container while protecting the remaining contents of the container from the surrounding environment.

These and other objects in the nature and advantages of the present invention will be more apparent from the following detailed description, taken in conjunction with the drawing wherein:

3,394,464 Patented July 30, 1968 FIG. 1 is a sectional view of one embodiment of the present invention in use; and

FIG. 2 is a sectional view, similar to FIG. 1, utilizing a different transfer-ring procedure.

To preserve the purity of degradable materials, such as pesticide chemicals, or other materials which are subect to contamination from any surrounding atmosphere, normally air, which pure materials are retained in containers, it is necessary that such containers be tightly sealed to prevent the entry of the surrounding atmosphere. In certain laboratory procedures, such as various testing procedures for pesticidal chemicals, it is necessary to remove portions of the sensitive material from its container while retaining the remainder of the material withinthe container for a later use. If the containers are merely opened to remove the sensitive materials, such as pesticide chemicals, the surrounding atmosphere, e.g., air (containing oxygen and water vapor), will enter while the container is open and thereby have an adverse effect on the remaining contents. If the materials contained are chemicals which are degraded by oxygen and water vapor, such chemicals must be protected from the surrounding air during opening of the container, while transferring a sample for use (such as for a reference standard).

The present invention utilizes a simplified device for protecting the contents of a container, such as a sample vial, during opening thereof for removal of a sample, by flushing the surrounding atmosphere from adjacent the mouth of the container before, during and after the container has been opened and closed.

In its most simple form, a transfer hood 10 is provided that fits over a sample vial 12. The hood 10 is generally cup shaped, open at the top, for insertion therein of a suitable chemical removing means such as a spatula or a syringe 20. The hood 10 is provided with suitable means for connection thereof with the via] 12 so that the mouth of the vial projects into the hood. The hood 10 is provided with a suitable passageway means near the bottom thereof for receiving a gas from an outside source. This gas is passed to the interior of the hood and distributed therein to flush the surrounding atmosphere therefrom.

Noting FIG. 1, it may be seen that in its preferred form the hood 10 fits tightly over the sample vial 12 and has a large opening at its other end for insertion of the chemical removing means. The hood 10 has a chamber 14 which, in the preferred embodiment, is only 3 centimeters high and has a diameter of about 4 centimeters. The hood 10 contains a perforated ring 16 for the distribution of the gas which is fed thereto through a passageway 22 as shown by the arrow G. The hood 10 has a constricted bottom 18 for attachment to the vial 12.

s The hood 10 may be formed of any suitable material such as glass, plastic or metal. Glass is the preferred material from which the entire device, including the tubular annular ring 16, is formed.

In use, the hood 10 is slid over the mouth of a vial 12 to tightly engage with the side Walls thereof along the constricted portion 18, and so that the mouth of the vial is located within the annulus of the tubular distributing ring 16.

When it is desired to transfer solid material from a container, such as shown in FIG. 1, a suitable gas is fed through the passageway 22, into the annular distributing ring 16 and then into the chamber 14 of the hood 10 to flush out the surrounding atmosphere. The gas fed is preferably an inert gas, although an inactive gas such as nitrogen will be suitable for most purposes; depending on the materials contained (to be transferred and protected) the gas may vary. After the surrounding atmosphere has been flushed from the chamber 14, the flow of gas may then be reduced to about 1 liter per minute (for the size chamber 14 given above, this amounts to 30 exchanges of atmosphere within the chamber per minute). The vial 12 in this case is provided with a screw top 24, and such screw top is next unscrewed from the vial 12 and placed in the hood as illustrated in FIG. 1. A sample may then be withdrawn with a small spatula by passing the spatula through the chamber 14 and into the mouth of the vial and then by withdrawing same from the chamber 14. Next, the cap 24 is replaced on the vial within the hood 10 before shutting off the gas fiow.

Operations for liquid samples differ somewhat, noting FIG. 2. Here, a vial 121 has a screw cap 241 containing a perforatable element 242. In such a case it is not necessary to unscrew the cap 241. Once again, the chamber 14 is purged by flowing an inactive gas through the passageway 22 and then through the distributing ring 16, and then the gas flow is reduced as above. The syringe is placed within the hood 10 and is pumped to displace the air therein by the inert gas passing into the gas chamber 14. The perforatable portion 242 is then punctured by the needle of the syringe and the liquid sample withdrawn from the vial 121. If it is necessary to replace the perforatable portion 242, this may be done while the gas continues to flow. The perforatable portion 242 is preferably formed of a self-sealing material, and these are known in the art.

After the vial 12 or 121 has been rescaled, the gas flow may then be shut off.

During use, it is most desirable that the vial be held in a suitable support 30 which grips the vial 12 or 121 with a rubber holding means 32.

The hood 10 of the present invention is of extremely simple and inexpensive construction and, yet, is designed to facilitate transfer of sensitive chemicals while affording protection against contamination at decomposition from oxygen or moisture. The device is applicable to the transfer of any sensitive materials which may be contained in a small vial 12 or 121 and eliminates the need for large and expensive pieces of apparatus to accomplish this purpose.

It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.

What is claimed is: 1. A device for protecting chemicals or the like in a container from the surrounding atmosphere during transfer from the container of a portion of the contents, comprising:

a generally cup-like transfer hood having an opening therein for the insertion of chemical-removing means;

means to connect said transfer hood to a container with the mouth of the container projecting into said hood;

means to distribute a gas to the interior of said hood to flush the surrounding atmosphere therefrom; and passageway means for receiving gas from a suitable source and passing said gas to said gas distributing means, said gas distributing means comprising a perforated annular pipe connected to said passageway means and having perforations therein for the escape of gas therefrom into said hood, said annular pipe being adapted to surround the mouth of the chemical container.

2. A device in accordance with claim 1 wherein said transfer hood is adapted to fit over and tightly engage the container with the bottom of the container projecting from the bottom of said hood, and wherein the opening for insertion of the'chemical removing means is at the top of said hood, ancl 'said' passageway means comprises an inlet pipe at the side of said hood.

3. A method of transferring chemicals and the like from a container without permitting contact with the surrounding atmosphere, comprising:

placing an annular hood over the chemical container so that the mouth of said container extends into said hood, said annular hood having a-cavity therein, a large opening at the upper end communicating with the cavity, and gas inlet means near the lower end of the hood into the cavity;

passing a gas inactive to the chemical to be transferred through the gas inlet means and into the cavity so that the gas is released at a plurality of points simultaneously surrounding and slightly lower than the mouth of said container to flush therefrom the surrounding atmosphere;

maintaining said fiow of inactive gas through the gas inlet means and into the cavity to prevent reentry of the surrounding atmosphere of gas through the large opening into the cavity;

unsealing the chemical container and removing contents therefrom through the opening in the presence of the said flow of inactive gas surrounding the mouth of the container;

rescaling the container; and

shutting 01f the gas flow.

4. A method in accordance with claim 3 wherein said container has a perforatable cover and said unsealing and removing contents from said container comprises passing the needle of a syringe into said hood through the large opening, pumping the syringe to fill same with inactive gas, passing the needle through said perforatable cover, Withdrawing said contents into said syringe, and withdrawing the needle from the container and then from the hood.

5. A method in accordance with claim 3 wherein said gas is inert.

6. A method in accordance with claim 3 wherein said gas is nitrogen.

References Cited UNITED STATES PATENTS 2,744,629 5/1956 Vine 3436 XR 2,786,740 3/1957 Taylor et al. 3l2l 3,026,730 3/1962 Howarth et al. 73425.4 3,191,640 6/1965 Hackett 14163 KENNETH w. SPRAGUE, Primary Examiner. 

